First computer build need advice

[Serenete]

I am debating on buying or building my own computer, I would like to build and use linux os but I'm just not sure how difficult it will be.
It will be used to play wow, download cd's, light photo editing and maybe a few other games I don't think wow really needs a great video card so since I am limited on funds I'm chosing to get that later and just use the one on the mobo. This is what I have come up with so far any suggestions would be great or anything i am missing just keep in mind i am trying to keep everything within 600-700 dollars thx.

A406-1054 :: Xion Solaris Black/Green ATX Mid-Tower Case with Clear Side, Front USB and Audio Ports and 450-Watt Power Supply (13 lbs)

MBM-8200-9500 :: XFX GeForce 8200 Motherboard CPU Bundle - AMD Phenom 9500 2.20GHz Retail Processor (3 lbs)

or

ASUS M3N78-EM AM2+/AM2 NVIDIA GeForce 8300 HDMI Micro ATX AMD Motherboard
AMD Phenom 8750 Toliman 2.4GHz Socket AM2+ 95W Triple-Core Black Edition Processor Model HD875ZWCGHBOX


TSD-500AAKS :: Western Digital Caviar SE16 500GB Hard Drive - 7200, 16MB, SATA-300, OEM (1.55 lbs)


ULT31799 :: Ultra Internal 3.5" Floppy Drive w/Multi Card Reader Black (0.85 lbs)

L12-1180 :: Lite-ON IHAP422-08 DVD Burner - 22X DVD+R, 22X DVD-R, 8X DVD+R9, 8X DVD-R9, 12X DVD-RAM, 8X DVD+RW, 6X DVD-RW, 16X Read, 32X CD-RW, 48X Read, LightScribe, IDE (2.2 lbs)

P33-5096 :: Patriot 4GB DDR2 RAM 2GB USB Drive 3DMark Bundle - 4096MB PC8500 DDR2 1066MHz, Patriot 2GB Razzo USB Flash Drive, Future Mark's 3DMark Vantage Software (0.1 lbs)


S445-D19006 :: Acer AL1916WAB 19" Widescreen LCD Monitor - Refurbished, 5ms, 700:1, WXGA+ 1440x900, VGA(D-sub), Black (13.95 lbs)

Thx

Should I just buy one and forget about trying to build my own ?